Enzyme Histochemical Localization of Peroxidase Activity in the Oviduct of Immature, Laying and Non-laying Hens

Abstract

Peroxidase may play roles in innate host immunity and affect the sperm survivability in hen oviduct. The aim of this study was to localize the peroxidase activity in the oviduct of hens and to examine whether the activity is affected by the developmental stages of the oviduct. The oviducts were collected from immature, laying and non-laying White Leghorn hens. Formalin-fixed oviductal tissues were processed for frozen sections and incubated with reaction mixture containing diaminobenzidine and H₂O₂. No peroxidase activity products were found in the surface epithelium of the infundibulum, magnum, uterus and uetero-vaginal junction (UVJ), in the tubular glands of magnum, isthmus and uterus, and in the sperm storage tubules in the UVJ. The activity was occasionally observed in the surface epithelial cells in the isthmus. The surface epithelial cells of the vagina contained dense peroxidase reaction products, which were distributed at the bottom region of the secondary folds. The density of reaction products and their distribution were reduced in non-laying hens, and the oviducts of immature hens contained no peroxidase reaction products. These results suggest that the surface epithelium of the vagina contains peroxidase activity in laying hens, which may play roles in innate host immunity and affect the sperm viability passing the vagina. The vaginal peroxidase activity is likely to be changed in association with the developmental stage of the oviduct.